Expandable core-former



Oct. 18, 1966 D. LONG 3,279,741

EXPANDABLE CORE-FORMER Original Filed Aug. 25, 1960' 5 Sheets-Sheet l 13 5 FIG. 3 550 54@ 56o l l l f 5 l f r l l a n 5 f l 5 l u n a a n l l f f l n i a l i f l l l l l l l l l 1 l l n f r n n a f l f r r l l n l l f a n a u l n f u l l a l f f 4 f 4 i M 'JM Oct. 18, 1966 D. LONG 3,279,741

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Oct. 18, 1966 L. D. LONG 3,279,741

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United States Patent() M 3,279,741 EXPANDAIBLE CORE-FORMER Leonard D. Long, Long Construction Co., P.0. Box 288, 2110 Mt. Pleasant St., Charleston, S.C. Application Aug. 1, 1962, Ser. No. 215,218, now Patent No. 3,210,039, dated Oct. 5, 1965, which is a division of application Ser. No. 51,972, Aug. 25, 1960, now Patent No. 3,090,093, dated May 21, 1963. Divided and this application July 19, 1965, Ser. No. 473,116

7 Claims. (Cl. 249-181) This invention relates to a core-former, and more particularly to an expandable core-former for producing cores in cored building blocks and the like. This application is a division of my copen-ding application Serial No. 215,218, filed August 1, 1962, now Patent No. 3,210,039, issued October 5, 1965, and which is a division of my application Serial No. 51,972, filed August 25, 1960, now Patent No. 3,090,093, issued May 21, 1963.

It is an object of my invention to provide a core-former which can be expanded by a rotational thrust force, which can be uniformly expanded throughout its length, which can be lexpanded against the action of substantial counterforces, which can be maintained in a fixed position and orientation during its expansion, and which will prove sturdy and durable in use.

In accordance with one form of my invention, the coreformer comprises a plurality of core segments having inwardly presented thrust-receiving faces which are operatively engaged 4by thrust-transmitting cam means mounted on a first shaft interposed between the core segments and rotatable to cause said cam means to move the core segments into spaced relation to each other for expanding the core-former. Conveniently, the core segments are operatively connected to means on said first shaft whereby upon reverse rotation of said first shaft said core segments will be moved toward each other to collapse the core-former.

A plurality of face plates are operatively connected to the several core segments to bridge the spaces between said segments and prevent the material being cored from entering into the interior of the core-former from the sides thereof when said core-former is expanded. Preferably, the opposed ends of the core segments are also operatively connected to plate means which prevent the material being cored from entering into the interior of the core-former from the ends thereof. Conveniently, the plate means at one end of the core-former is provided with a pilot for guiding the core-former into a mold and releasably retaining it in a fixed position therein, and the plate means at the opposite kend of the vcore-former is connected to a second shaft for moving the core-former into and out of operative position in a mold.

` Other objects and features of my invention will become apparent from the more detailed description which follows and from the accompanying drawings, in which:

FIG. 1 is a vertical section of an expandable coreformer embodying my invention;

FIG. 2 is a horizontal section taken on the line 2 2 of FIG. l;

FIG. 3 is a horizontal section similar to FIG. 2, but showing the core-former in expanded position;

FIG. 4 is a horizontal section taken on the line 4 4 of FIG. l, but with portions thereof broken away;

FIG. 5 is an enlarged isometric view of one of the cam followers shown in FIG. 2;

FIG. 6 is an enlarged isometric view of the cam shown in FIG. 2;

FIG. 7 is an enlarged isometric View of one of the core segments shown in FIG. 2;

FIG. 8 is an enlarged bottom plan view of the spider plate shown in FIG. 4;

3,279,741 Patented Oct. 18, 1966 ICC FIG. 9 is an enlarged isometric view of one of the face plates shown in FIG. 2;

FIG. 10 is a bottom plan view of the in FIG. 1; and

FIG. 11 is a top plan View of the pilot plate shown in FIG. 10.

My core-former is adapted -to be used in combination with an apparatus of the type disclosed in my Patent No. 3,090,093, issued May 2l, 1963, for producing molded components having cores formed therein. The construction of my core-former is such that it can be inserted in a collapsed condition into an appropriate mold prior to the addition of the material to ybe molded, and then expanded to compress said material against the inwardly presented mold walls. This permits the formation of highdensity molded articles having cores formed therein.

For ease of description, the core-former is described herein as being used to produce cored building blocks formed from an aggregate mixture. It is to be understood, however, that my core-former can be used `for producing various other types of cored elements.

The core-former is carried on one -end of a shaft 510 adapted to be moved axially for moving the core-former in-to and out of a mold. As shown in FIG. vl, a spider plate 512 is rigidly mounted on the end of the shaft 51'0 for connecting the core-former to said shaft. Conveniently, the spider plate 512 has a lateral extent substantially as large as the lateral extent of t'he core-former in collapsed position, and has its edges beveled, as at 514. The core-former is expanded by means of a rotatable shaft 516 extending upwardly through the shaft 510 for connection to a rotational power source.

As shown in FIG. 2, the core-former -is provided with four generally L-shaped core segments 518 having inwardly disposed thrus-t-receiving faces 519 and slidably connected to the plate 512. To this end, a T-shaped key 520 is mounted on the upper end of eac'h of the core segments 518 and is slidably received in a T-shaped keyway 522 formed in the lower face of the plate 512. As shown in FIG. 8, lthe keyways 522 are disposed on the oblique axes of the plate 512 and extend inwardly from each of its corners.

Similarly, a T-shaped key 524 is mounted on the lower face of each of the core segments 518, and is slidably received in a T-shaped keyway 526 disposed on an oblique axis of the upper face of a pilot plate 528. A rectangularly shaped pilot 530 extends downwardly from the pilot plate 528 for reception in an opening in the bottom of a mold upon movement of the core-former into said mold, said pilot engaging the faces of said opening to prevent the core-former from Vrotating in the mold. AS shown in FIG. l, the bolt 531 extends upwardly through the pilot to rotatably connect the pilot plate 528 to the lower end of the shaft 516. Conveniently, the pilot plate 528 has its edges beveled, as at 532, and has a lateral extent corresponding to the lateral extent of the spider pla-te 512. Thus, the pair of plates 512 and 528 operatively interconnect the four core segments 518 and enclose the ends of the core-former.

The rotatable shaft 516 extends downwardly through the opening in the shaft 510 to thus interpose its lower end between the four core segments 518. As shown in FIG. 6, the ends of this lower portion of the shaft 516 are delined by a pair of heads 533 which `have a larger diameter than the remainder of the shaft `and abut the opposed faces of the plates 512 and 52810 thus hold the shaft and core segments in lfixed vertical position with respect to each other. Four angularly disposed recesses 534 are provided between lthe heads 533, and as shown in FIG. 6, each of said recesses has a teardrop configuration including a cam face 535 adapted to bear against a vertically extending cam follower 536. Each of the cam folpilot plate shown lowers 536 is swingably mounted in one of the recesses S34 by a pair of pins 537 interconnecting the ends of the cam follower to the heads 533. Each of the cam followers is also provided with a pair of studs 540 swingably joined to the core segments 518 by means of clips 542 mounted on said core segments adjacent their upper and lower ends. As shown, each of the clips extends inwardly from one of the thrust-receiving vcore segment faces 519 with its apertured inner end rotatably received over one of the studs 540. In -this manner, the 'four core segments 51S are operatively connected to the shaft 516 and to each other with their thrust-receiving faces held in engagement with the cam followers S36.

In order to prevent aggregate from entering the coreformer when it is in expanded position, I mount a vertically extending face plate 548 on each of the core segmen-ts 518 as by countersunk screws 550. As shown in FIG. 3, each of the face plates 550 has a width corresponding to the width of the core-former in collapsed position so that it bridges the space between a pair of adjacent core segments when the core-former is in expanded position. Extending inwardly from the upper and lower ends of the face plates are top and bottom cover plates'552 and 554, respectively, extending inwardly over the outer faces of the spider plate S12 and pilot plate 528 to abut the shaft 510 and pilot 530. In order to guide the movements of the cover plates during expansion and contraction of the core-former, the outer faces of the spider and pilot plates are provided with pluralities of keyways 556 which slidably receive keys 558 formed on the inner faces of each of the cover plates 552 and 554. As shown, the keys 55S and keyways 556 are disposed at a 45 angle to the transverse core-former axes, the angle of movement of the face plates 548 and core segments 518. Conveniently, the edges of the farce plates 548 and cover plates 552 and 554 are beveled, as at 560, to screed any aggregate from the surfaces on which they slide during contraction of the core-former.

Thus, the operation of the core-former shown in FIG. l-ll may be described as follows: The shaft 510 is moved axially to position the coreaformer in a mold, with the -pilot S30 seating said core-former in an operative position therein. When the shaft 516 is rotated through a 45 angle in a clockwise direction as viewed in FIG. 2, the cam faces 535 will bear against the cam followers 536 to move them from their collapsed positions in which they are parallel to the transverse axes of the core-former to their extended positions in which they lie on the oblique axes of the core-former, said cam followers pivoting about the axes of the pins 537. As the cam followers are moved toward their expanded positions, they bear against thrust-receiving faces 519 on the core segments to move said core segments outwardly into spaced relation to each other. This outward movement of the core segments on the oblique axes of the core-former is guided by the keys 520 and 524 sliding in the keyways 522 and 526 in the spider plate 512 and the pilot plate 528. With the core segments in this expanded position shown in FIG. 3, the face plates 548 bridge the spaces between the spaced pairs of adjacent core segments along the side faces of the core-former to prevent the entry of aggregate therein. And the top and bottom cover plates 552 and 554 cooperating with `the spider plate 512 and pilot plate 528 prevent the entry of aggregate into the core-former from the top and bottom thereof.

To retract the core-former into its collapsed position, the shaft 516 is rotated through a 45 angle in a counterclockwise direction as viewed in FIG. 3. This rotational movement of the shaft pulls the cam followers S36 inwardly with the studs 540 on said cam followers pulling the core segments 518 inwardly by means of the clips 542. Such inward movement of the core segments is also guided by their keys 520 and 524 moving in their respective keyways in the plates 512 and 528, During this inward movement of the core segments, the beveled edges on the face plates and the spider and lpilot plates will slide along the outer faces of the core segments to screed any aggregate therefrom, with the beveled edges of the top and bottom cover plates S52 and 554 screeding the outer faces of said spider and pilot plates.

I claim:

1. An expandable core-former, comprising a plurality of core segments having L-shaped cross-sections movable with respect to each other between a retracted position in which they abut each other and an extended position in which they are in spaced relation to each other, each of said core segments having a thrust-receiving face on an oblique axis of the core-former, a first shaft movable for moving the core-former to and from an operative position in a mold and having means slidably connected to said core segments for guiding the movements of said core a xed axial position on said second shaft whereby rotatably carried in said first shaft and interposed between said core segments, a plurality of cam faces on said second shaft, said cam yand thrust-receiving faces extending substantially the lengths of said core segments, a plurality of cam followers swingably connected to said second shaft and said core segments engageable with said cam faces and thrust-receiving faces in abutting face to face relation along substantially the lengths thereof upon rotation of said second shaft in one direction to `simultane-` ously force said core segments outwardly :into spaced relation to each other to expand the core-former and to pull said core segments inwardly upon rotation of said second shaft in an opposite direction to collapse said coreformer, and means bridging and closing the spaces between tops, bottoms, and sides of said core segments.

2. An expandable core-former as set forth in claim 1 in which said core segments comprise four core segments movable with respect to each other on the oblique coreformer axes, said cam faces comprise four angularly spaced elongated cam faces radially offset with respect to the axis of said second shaft, and said cam followers comprise four elongated cam followers swingably mounted in a fixed axial position 1on said second shaft whereby rotation of sai-d second shaft through an angle of 45 in said one direction will cause said cam faces and cam followers to force said core segments outwardly in spaced relation to expand the core-former.

3. An expandable core-former as set forth in claim 2 in which said cam Ifaces are formed in said second shaft and said cam followers are mounted on said second shaft in opposed pairs with each of said pairs being disposed on an oblique core-former axis when the core-former is in expanded position.

4. An expandable core-former as set forth in claim 1 in which a pilot plate rotatably connected to said second shaft is slidably engageable with one end of said core segments and a pilot projects outwardly therefrom for releasably retaining the core-fonmer in a fixed non-rotatable position in a mold, and said means bridging the spaces between said core segments comprises a plurality of face.

plates on said core segments, said face plates having cover plates at each of their ends extending inwardly over the means on said first shaft and the pilot plate to close the ends of said core-former.

5. An expandable core-former as set forth in claim 4 in which said cover plates are slidably received against said pilot plate and the means on said iirst shaft and keyed to each by mating keys and keyways extending ontwardly from the transverse core-former axes and parallel to the oblique core-former axes.

6. An expandable core-former, comprising a plurality of core segments having L-shaped cross sections rnovable with respect to each other between a retracted position in which they abut each other and an extended position in which they are in spaced relation to each other, each of said core segments having a thrust-receiving face on an oblique axis of the core-former, a first shaft axially movable for moving the core-former to and from an operative position in a mold, a spider plate Xedly mounted on said rst shaft and slidably keyed to one end of said core segments, a second shaft rotatably carried in said rst shaft and interposed between said core segments, a pilot plate rotatably connected to said second shaft and slidably keyed to the opposed ends of said core segments, a pilot on said pilot plate for releasably retaining said core-former in a xed non-rotatable position in a mold, said second shaft having an enlarged portion rotatably carried against said spider and pilot plates, a plurality lof cam faces on said enlarged portion of said second shaft, said cam and thrust-receiving faces extending substantially the lengths of said core segments, ya plurality of cam followers swingably connected to said second shaft and said core segments engageable with said cam and thrustreceiving faces in abutting face to face relation along substantially the lengths thereof upon rotation of sai-d second shaft in one direction to simultaneously force said core segments outwardly into spaced relation to each other to expand the core-former and pulling said 20 core segments inwardly upon rotation of said second shaft in an opposite direction to collapse said coreformer, and means bridging and closing the spaces between tops, bottoms, and sides lof said core segments.

7. An expandable core-former as set forth in claim 6 in which each of said cam followers is swingably carried in a recess formed in said enlarged port-ion of said second shaft, and each said cam faces comprises one of the faces of said recesses.

References Cited by the Examiner I. SPENCER OVERHOLSER, Primary Examiner.

I. HOWARD FLINT, Examiner. 

1. AN EXPANDABLE CORE-FORMER, COMPRISING A PLURALITY OF CORE SEGMENTS HAVING L-SHAPED CROSS-SECTIONS MOVABLE WITH RESPECT TO EACH OTHER BETWEEN A RETRACTED POSITION IN WHICH THEY ABUT EACH OTHER AND AN EXTENDED POSITION IN WHICH THEY ARE IN SPACED RELATION TO EACH OTHER, EACH OF SAID CORE SEGMENTS HAVING A THRUST-RECEIVING FACE ON AN OBLIQUE AXIS OF THE CORE-FORMER, A FIRST SHAFT MOVABLE FOR MOVING THE CORE-FORMER TO AND FROM AN OPERATIVE POSITION IN A MOLD AND HAVING MEANS SLIDABLY CONNECTED TO SAID CORE SEGMENTS FOR GUIDING THE MOVEMENTS OF SAID CORE A FIXED AXIAL POSITION ON SAID SECOND SHAFT WHEREBY ROTATABLY CARRIED IN SAID FIRST SHAFT AND INTERPOSED BETWEEN SAID CORE SEGMENTS, A PLURALITY OF CAM FACES ON SAID SECOND SHAFT, SAID CAM AND THRUST-RECEIVING FACES EXTENDING SUBSTANTIALLY THE LENGTHS OF SAID CORE SEGMENTS, A PLURALITY OF CAM FOLLOWERS SWINGABLY CONNECTED TO SAID SECOND SHAFT AND SAID CORE SEGMENTS ENGAGEABLE WITH SAID CAM FACES AND THRUST-RECEIVING FACES IN ABUTTING FACE TO FACE RELATION ALONG SUBSTANTIALLY THE LENGTHS THEREOF UPON ROTATION OF SAID SECOND SHAFT IN ONE DIRECTION TO SIMULTANEOUSLY FORCE SAID CORE SEGMENTS OUTWARDLY INTO SPACED RELATION OF EACH OTHER TO EXPAND THE CORE-FORMER AND TO PULL SAID CORE SEGMENTS INWARDLY UPON ROTATION OF SAID SECOND SHAFT IN AN OPPOSITE DIRECTION TO COLLAPSE SAID COREFORMER, AND MEANS BRIDGING AND CLOSING THE SPACES BETWEEN TOPS, BOTTOMS, AND SIDES OF SAID CORE SEGMENTS. 